Packages for sterile storage are used in various technical fields, such as in medicine or in the food industry. Particularly in medicine, receptacles for storing and dispensing a sterile product often have to be kept sterile too, to avoid contamination of, for example, the surgical environment.
Products used in surgery are generally applied sterilely. Such products are, for instance, bone regeneration materials used for supporting the regeneration of bone tissue in dental implant surgery. Several package systems for bone regeneration materials have been developed in the past, all belonging to one of the following three groups:
A first group relates to syringes having a tube in which the bone regeneration material is contained. The syringe is sterilely enclosed in a pouch. Examples of sterile products packaged in such a package system are CrossBone® of Biotech International or Biogran® of 3i.
In a second group, the package system is a glass vial sealed by a plastic stopper and an aluminum lid. The glass vial is sterilely enclosed in a pouch. Examples of sterile products packaged in such a package system are Bio-Oss® of Geistlich Biomaterials and Cerasorb® of Curasan.
In a third group, the package system comprises an outer tray and an inner tray, both having a bottom portion and a cylindrical sidewall. The bone regeneration material is contained in the inner tray sealed with a first cover, and the inner tray is contained in the outer tray sealed with a second cover. Such a package system is called a “double blister”. An example of a sterile product packaged in such a package system is Ceros TCP® of Mathys Medical.
For applying the bone regeneration material contained in a “double blister”, the cover of the outer tray is peeled off and the sealed sterile inner tray is removed from the outer tray, i.e. by dropping it on the sterile surface. Thereby, only the sterile inner tray comes into contact with the sterile surface. The cover of the inner tray is then peeled off and a liquid—typically a sterile physiological NaCl solution or blood, which has previously been taken from the patient—is added to the granular bone regeneration material. The thus formed mass is then discharged from the inner tray and applied.
Discharging and applying the said formed mass from a known “double blister” as described above is troublesome and time consuming, since the dentist has to spoon out the said formed mass from the inner tray with a spoon or a spatula. Thereby, a considerable amount of the said formed mass is usually spilled. Further, there is always a residue in a tray which cannot be spooned out. This also contributes to a considerable loss of bone regeneration material.
In addition, contamination of the sterile mass is likely due to its relatively long exposure to the environment.